Influence of the Surface Energy of Polymer Alignment Layers on the Optical Quality of Smectic C* Liquid Crystal Cells

The problem of formation a reproducible spatially-uniform alignment of smectic C* ferroelectric liquid crystals (FLCs) in liquid-crystal (LC) cells has not been completely solved yet. We investigated aligning layers (anisotropic coatings) of different types (island and continuous). These layers contact with FLC in LC cells and form a selected direction for molecular orientation. It was investigated the influence of mechanical cycles numbers of rubbing polymer alignment layers made of polyvinyl alcohol and polyamide 66 on the optical quality of FLC cells to which electric field was not applied. It is shown that there is an optimal number of rubbing cycles for obtaining the best optical quality of FLC cells; the number of cycles is individual for each polymer alignment layer and coating type.